The internal mix is when the air and the paint both mix inside of the airbrush. This will create a atomized fine dot spray pattern. This makes the internal mix a good choice for fine detailed work in your airbrush art. The point at which they come together is in the head assembly. The external mix is where the air and paint come together outside of the head assembly or the fluid assembly. While an experienced airbrush artist may know this a beginner may not, so it is worth mentioning. When doing airbrush art on skin make sure you are using airbrush paint that is designed for the skin. Usually this will be sold as airbrush body paint or airbrush temporary tattoo ink. These are the only types of airbrush paints that are safe to use on the human skin. But as long as your project is made from the above material you can use water soluble acrylics for your airbrush art designs. Depending on which brand of acrylic paint that you go with, you may need to thin it down so that it flows freely through the airbrush. Also some acrylic paints require that they be heat set if used on clothing. Depending on the size of your stencil you can probably create more than one stencil from this plastic folder. If you purchase the see through folders then you can use these for stencils even if you are limited to tracing your design onto the plastic folder prior to cutting it into a stencil for your airbrush art. The kit runs around $544 where as individually purchased these items would cost you around $639. For those of you who have experience in airbrush art tattoos and want a kit that will allow you to open up your own business doing airbrush art tattoos professionally, Airbrush Bodyart has you covered. They offer the Airbrush Volume Parlor 2000 kit. Airbrush Art Expert-Pamela Shanteau Pamela Shanteau is a renowned airbrush artists who's airbrush talent streams over multiple styles and surfaces. She is recognized among her peers and airbrush enthusiasts for your custom airbrush art. Her surfaces choices for her airbrush art include automotive and motorcycles and the body.